The present invention relates to a fabrication method of optical interconnection component enabling low-cost and high-precision alignment of component, and to optical interconnection component itself.
In optical communication devices and in optical transceivers used for such communication devices, there is such a case that the component (hereinafter referred to as an optical interconnection component) for fixing the optical fiber to be coupled optically to light emitting devices and light receiving devices (hereinafter referred to as optical devices) is formed on the substrate on which the optical devices are mounted.
As for the fabrication method of the optical interconnection component required to establish a reliable optical coupling between the optical fiber and the optical device, there are two methods; an active method and a passive method. The active method adjusts the relative position between the optical fiber and the optical device by monitoring the light receiving signal in transmitting actually the light through the optical fiber. The passive method adjusts the relative position between the optical fiber and the optical device by using a visually recognizable mark or using a means for adjusting mechanically the relative position, without transmitting actually the light into the optical fiber. The passive method, which resultantly excludes a try-and-error process, is suitable for mass production.
As for the fabrication method for the optical interconnection component using the passive method, such methods as disclosed in the following Patent Reference 1 and Non-Patent Reference 1 are known as prior arts.
In the method of Patent Reference 1, at first, a concave part to be used as the part, in which the optical device is placed and a V-groove to be used as the part in which the optical fiber is disposed, are formed on the silicon substrate by applying an anisotropic etching process, and next, the optical device is installed in the concave part and the optical fiber is disposed into the V-groove so that the end of the optical fiber may be in contact with the optical device at the precise relative position, and finally the optical fiber is fixed with an adhesive material.
In the method of Non-Patent Reference 1, the optical fiber in which a 45-degree mirror is preformed through a dicing process is disposed and fixed in the V-groove formed at the upper structure, and the optical device is fixed at the lower structure, and then, the upper structure and the lower structure are made assembled together so that the optical device may be coupled optically to the optical fiber through the 45-degree mirror. In order to adjust precisely the relative position between the upper structure and the lower structure, a V-groove is formed at the lower structure so as to oppose to the V-groove at the upper structure and a guide pin with its cross-section shaped in a round is disposed between the V-grooves at the upper and lower structures so as to adjust the relative position in the width direction of the V-groove. In order to adjust the relative position in the longitudinal direction of the V-groove, the relative position between the optical fiber and the optical device is adjusted by sliding those structural elements in a semi-passive manner.
[Patent Reference 1] JP 11-337777 A (1999).
[Non-Patent Reference 1] Suzuki et. al. “New Concept of Mount Structure for 10 Gb/s and 4 ch Optical Interconnection Modules” (in Japanese) P. 265, Proceedings from Electronics Society, the Institute of Electronics, Information and Communication Engineers (2005).